Propeller



Jan; 26, 1932. v F. E. WEl CK 1,842,466

PROPELLER Filed Feb. 6, 1929 2 Sheets-Sheet l FRED E. WE/CK op E/ Jan.26, 1932. w lc 1,842,466

PROPELLER Filed Feb. 6, 1929 2 Sheets-Sheet 2 ee-0 f, l4 e/ak' /4TTOFA/E/ Patented Jan. .26, 1932 FRED E. WEICK, OF LANGLEY FIELD,HAMPTON, VIRGINIA PBOPELLER Application filed February 6, 1929. SerialNo. 337,978.

(GRANTED UIIDER THE ACT MARCH 3, 1883, AS AMENDED APRIIl 30, 1928; 3700. G. 757) propeller which will be relatively light in weight and whichwill lend ltself to easy manufacture and low manufacturing costs on aproduction basis.

Another object of this invention is to provide a simple and economicalmethod of manufacture of the propeller blades.

' With the above and other objects in view the invention consists in thenovel features of construction and the combination and arrangement ofparts as will hereinafter more fully appear from the description andclaims and the accompanying drawings, in which- Fig. 1 is an elevationof a propeller con-' structed in accordance with this invention lookingat the convex side of the blades.

Fig. 2 is an elevation similar to Fig. 1 look in at the concave side'ofthe blades.

Fig. 3 is a section taken on line 3-3 on 'Fi 1.

Fig. 4 is a section taken on line 4-4 on Fi 1. a

Fig. 5 is an enlarged elevation of one of the blades detached from thehub looking at the convex face thereof. a I

Fig. 6 is an elevation similar to Flg. 5 looking at the edge of theblade.

Fig. 7 is a section taken on line 7-7 on Fi 5.

ig. 8 is a section taken on line 8-8 on Fig. 5. I

Fig. 9 is a section taken on line 9-9 on Fig. 5. y

Fig. 10 is a fragmentary section of a portion of the blade rootillustrating a modified form of groove for attaching purposes.

Fig. 11 is a fragmentary section of a portion of the blade rootillustratin another modified form of groove for attac ing puroses.

Fig. 12 is an elevation of the dies used for stamping out a blade from asingle blank of materia 1 Fig. 13 is a series of sections taken on linesA--BC-DE and F on Fig. 12; and

Fig. 14 is a perspective of the dies separated and a blank of materialfrom which a blade is pressed.

Like numerals of reference indicate like parts throughout the severalfigures, in which: 10 and 11 indicate dies for pressing a sheet ofmaterial 12 of uniform thickness to provide a blade with the properconcave and convex faces. At one end the sheet of material is formed ina cylinder or part cylinder 13 for attachment to the hub proper in sucha manner that the blade may be rotated with respect to the hub andfastened at any of a variety of pitch angles. The cylinder or partcylinder 13 has a transverse groove 14 pressed therein that forms acircular rib on the inner face of the cylinder and is seated when inoperative position in a groove formed in the hub proper. This isillustrated to an advantage in Fig. 3. A clamping ring 15 is placed inthe grooved portion 14 of the cylindrical root portion 13 and a secondband such as the flat band 16 may be placed about the portion 13adjacent the ring 15 if so desired-as an additional fastening means. InFigs. 10 and 11 modified forms of ring receiving grooves 17 and 18 areshown.

After the blade is stamped or pressed from a flat sheet of material theforward or convex side is completely formed as to shape, angle andfinish, except for polishing. The cross section of the blade is thenbrought to the form of a good airfoil by cutting the edges of theconcave side off substantially straight across as at 19, Figs. 8 and 9,to provide flat surfaces at the leading and trailing edges of the.concaved driving face of the blade and disposed in the planes of thechords of the respective blade sections or elements. As clearly shown inFig. 5, these surfaces 19 increase in width as they approach the tip ornarrow end of the blade which increases in width from tip to root. Thisresults from the fact that the camber of the blade attains its highestpoint or peak at approximately one third of thechord or blade width backof the ing to produce the finished product. The

blades thus formed can-easily be made in.

quantity production at a minimum cost. The cylindrical hub portion 13allows for the ready attachment of the blade to the hub proper and forthe rotation thereof with respect to the hub proper to obtain thedeslrable pitch angle in which position it may be secured by thesecuring bands.

The propeller or blade thereof, formed in accordance with the invention,has unique and important features. The fact that sheet material (metalor other suitable sheet material) and only a single sheet thereof, isused for the formation of an aerodynamically eflicient blade, is ofparticular interest not only from the standpoint of economy includingmanufacture (material, simplicity and ease of construction, time, etc.)but also from the stand point of the high ratio of strength per unit ofweight. In connection with the matter of strength it should be notedthat the-invention rovides a blade or a propeller having a high actor ofinherent rigidity due to the structural formation, tending to overcomedeflecting forces which would in turn tend to destroy or impair itsaerodynamical and/or structural eificiency. Yet the blades are efficientand therefore effective for their purposes because they are given a goodaerofoil form. The curling inward of the edges of the blades as theedges approach the root or hub portion, whether the curling be extremeas illustrated as at 13 or less so as shown farther out, gives increasedstrength as will be appreciated and may assist in the securing of theblade or blades to a hub or rotor member proper. The many otheradvantages of the invention should be apparent to those skilled in theart.

Hence, while'I have illustrated ,and described what may be termed atpresent a preferred form ofthe invention, many changes may be madetherein and the invention may be embodied in many other forms bearinglittle resemblance in some respects to that illustrated, without dearting from the spirit of the invention or the scope of the appendedclaims.

I claim 1. An aeronautical propeller blade having concavo-convexaerodynamically efiicient blade sections each of which has the leadingand trailing edges of its driving face flattened in the plane of thechord of the sections.

material in such man-- 2. An aeronautical propeller .blade of pressedmetal of uniform cross sectional thickness having concave-convexaerodynamically eflicient blade sections gradually increasing in widthfrom root to tip of the l and having the leading and trailing edges oftheir respective driving faces flattened to provide smooth surfaces inthe planes of the chords of the sections and decreasing in width fromtip to root of the blade.

3. An aeronautical propeller blade of pressed metal of uniform crosssectional thickness and tapering in width from root to tip havingconcavo-convex aerodynamically efficient bladesections of substantiallythe same negative camber on the driving face as positive camber on theback, the sides of the blade at the root being curled inwardly of theleading and trailing edges to provide a tubular root portion changinggradually from a relatively small elliptical cross section at its innerend to a relatively large circular section at its outer end.

4. In a propeller, a cylindrical hub, a blade from root to tip ofconcave-convex aerofoil section having the sides thereof at the root ofthe blade elongated on arcuately converg ing lines forwardly of theconcave face of the blade to provide a tubular root section ofcylindrical cross-section embracing the said hub and rotatable about thesame, andmeans for securing said root section tothe said hub.

5. In a propeller, a hub having a circumferential groove, a blade ofconcavo-convex aerofoil section having the sides thereof at the rootelongated on converging lines forwardly of the concave face of thesection to provide a tubular root portion embracing the hub andconforming to the shape of the latter, each of said elongated sideshaving a rib seating in the groove of the hub, and clamping meansembracing the said hub and root portion.

6. In a propeller, a cylindrical hub having a circumferential oove, ablade of concavocovex aerofoil section having the sides thereof at theroot arcuately elongated on converging lines forwardly of the concaveface of the section to provide a substantially cylindricalhub-encircling root portion, each of said elongated sides having aportion thereof formedto present a groove in the outer face of the rootportion and a rib on the inner face thereof, the said rib being seatedin the groove of the hub, a clamping ring seated in the said grooves ofthe root portion, and means for .ex anding and contracting the rin Anaeronautical propeller b ade completely formed from a single flat sheetof metal of uniform cross sectional thickness to provide aroot portioncurved in the arc of a circle and a series of concavo-convexaerodynamically efiicient blade elements decreasing in width from root.to tip of the blade, and having substantially the same negative adecamber on the driving faceaspositive camber on the back with the camberattainin its peak at approximately one-third of the 0rd I of the bladewidth back of the leading edge,

said blade elements having the'leading and trailing edges of theirconcave sides flattened in the planes of the chords of the respectiveelements.

In testimony whereof I affix my signature.

FRED E. WEICK.

